Geographical variation in prevalence of hypertension within The Gambia

Hypertension has become an important public health problem for sub-Sahara A frica. In a previous nationwide study, we observed a high degree of geograp hical variation in the prevalence of diastolic hypertension. Geographical v ariation provides essential background information for the development of c ommunity randomised trials could suggest aetiological mechanisms, inform co ntrol strategies and prompt further research questions. We designed a follo w-up study from the nine high-prevalence communities, and from 18 communiti es where hypertension was found least prevalent (controls). In each communi ty, 50 households were randomly selected. In each household, an (unrelated) man and woman were enrolled. The risk for hypertension (blood pressure gre ater than or equal to 160/95 mm Hg) was higher in the high prevalence commu nities compared to the control villages (adjusted OR = 1.7, 95% Cl 1.3-2.2) . The observed coefficient of variation in hypertension prevalence, k, was 0.30. Thus we confirmed significant geographical variation in prevalence of hypertension over time, which has implications for planning of interventio ns.